Q. Is it possible to propagate my `Lemon Wave' hydrangea from cuttings? Please provide details.
--Renee Preston Kunkel, Vernon Hills
A. Hydrangea macrophylla `Lemon Wave' is a variegated bigleaf hydrangea hardy to Zone 6, although it can survive in our Zone 5 in a protected site.
To propagate bigleaf hydrangea, prune off several 5- to 6-inch softwood cuttings from the plant in June or July. Each cutting should have two sets of leaves.
Remove the lower set of leaves and dip the stem in a rooting hormone, making sure the powder touches the cuts or scars on the stem left when you removed the leaves.
Plant the cuttings in a seed tray filled with moist soilless mix.
Cut each of the remaining leaves in half, so the leaves will be more in proportion to the small root system that will develop for each cutting.
Put the tray in a plastic bag to retain humidity and set it outside in dappled sunlight. Be sure the mix stays moist.
In six to eight weeks, the plants should develop strong enough roots so they can be transplanted to 1-gallon pots. Fertilize with a very dilute, organic product and set the pots outside in a sunny spot.
When cold weather arrives, move the plants to a very sheltered spot, remove their pots and mulch their root zones heavily. This "heeling in" should protect them over the winter unless the weather is unusually harsh. Or you can plant them in the ground and then mulch heavily.
In spring, plant them in your garden in a sheltered spot similar to where you successfully grew the parent plant.
Q. We have a little critter living under my ajuga ground cover on the perimeter of the property. It is several inches long and gray with a blunted snout and squeaks loudly when my cat plays with it.
--Ann Wilson, St. Charles
A. You probably have a nest of meadow voles under that ajuga.
They do not hibernate in winter but are active all year long, chewing vegetation and burrowing into the roots of small trees and shrubs as well as removing the bark from these woody plants. Their damage ranges from cosmetic to deadly.
Since you have pets, chemical controls are not advised. You can trap the voles with mouse snap traps (keep the pets inside until they're trapped) or try to eliminate their nesting area.
This would involve cleaning up the ground cover bed, pulling all mulch or plant material away from the trunks of trees and shrubs and mowing your grass quite low in areas you suspect harbor nests.
Q. Is diatomaceous earth effective as a garden insecticide?
--Aileen Demakos, Bolingbrook
A. Diatomaceous earth is not an earth or soil product, but a finely powdered substance made from the skeletons of sea and freshwater organisms known as diatoms.
While diatomaceous earth feels soft as talcum powder to us, the microscopic particles have very sharp, jagged edges capable of cutting certain soft-bodied insects, causing them to dry out and die.
It is not intended to be used for all garden insects. Home gardeners most commonly use it as a slug control
Lee Randhava writes for the Chicago Botanic Garden in Glencoe.